from sqlalchemy import String, Text, Boolean, Integer, ForeignKey, func
from sqlalchemy.orm import Mapped, mapped_column, relationship
from datetime import datetime
from typing import Optional
from app.database import Base


class CalendarEvent(Base):
    __tablename__ = "calendar_events"

    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    title: Mapped[str] = mapped_column(String(255), nullable=False)
    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    start_datetime: Mapped[datetime] = mapped_column(nullable=False)
    end_datetime: Mapped[datetime] = mapped_column(nullable=False)
    all_day: Mapped[bool] = mapped_column(Boolean, default=False)
    color: Mapped[Optional[str]] = mapped_column(String(20), nullable=True)
    location_id: Mapped[Optional[int]] = mapped_column(Integer, ForeignKey("locations.id"), nullable=True)
    recurrence_rule: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
    is_starred: Mapped[bool] = mapped_column(Boolean, default=False, server_default="false")
    calendar_id: Mapped[int] = mapped_column(Integer, ForeignKey("calendars.id"), nullable=False)

    # Recurrence fields
    # parent_event_id: set on child events; NULL on the parent template row
    parent_event_id: Mapped[Optional[int]] = mapped_column(
        Integer,
        ForeignKey("calendar_events.id", ondelete="CASCADE"),
        nullable=True,
    )
    # is_recurring: True on both the parent template and all generated children
    is_recurring: Mapped[bool] = mapped_column(Boolean, default=False, server_default="false")
    # original_start: the originally computed occurrence datetime (children only)
    original_start: Mapped[Optional[datetime]] = mapped_column(nullable=True)

    created_at: Mapped[datetime] = mapped_column(default=func.now())
    updated_at: Mapped[datetime] = mapped_column(default=func.now(), onupdate=func.now())

    location: Mapped[Optional["Location"]] = relationship(back_populates="events")
    calendar: Mapped["Calendar"] = relationship(back_populates="events")

    @property
    def calendar_name(self) -> str:
        return self.calendar.name if self.calendar else ""

    @property
    def calendar_color(self) -> str:
        return self.calendar.color if self.calendar else ""